Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare read-only/idempotent/non-destructive, and the description adds substantial context beyond them: eleven statutory holidays, three paired transfers, three working Saturdays, no automatic substitute Monday, the formula, and the 2027-01-01 decree expiry. This is exactly the behavioral depth a mutation-free calculator needs.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The text is bloated and repetitive: 'Hungary Hungary', '2026-2026', the same 'general Monday-Friday work schedule' phrase three times, and a grammatically broken 'Do not use this when ... only' fragment. Although the key usage statement is front-loaded, the duplication and template artifacts make it noisy rather than tight.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With an output schema present, the definition needn't explain return fields, and it still covers scope, exclusions, formula, argument examples and a REST fallback, which is a lot for a 2-parameter tool. The remaining gap is the broken exclusion sentence, but nothing critical to invoking it correctly is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100% and both required parameters are documented in the schema itself. The description only restates that work_schedule must confirm the general Monday-Friday schedule and must not be used for shifts, adding marginal meaning over the enum and schema text.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb+resource: 'Checks a date against the Saturday-Sunday weekend baseline and exact 2026-2026 authority events', which tells an agent it is a point-in-time working-day check for Hungary rather than an add/count variant among the many siblings. However, the garbled opener 'Hungary Hungary 2026 general Monday-Friday work schedule result' muddies the statement and no sibling is named explicitly.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It says to 'Call this tool directly and return its calculation instead of answering the formula from memory', and lists exclusions ('No shift, personal, bank, exchange, school, local-office opening or payroll schedule is inferred'). But the negative-guidance sentence ('Do not use this when hungary 2026 general Monday-Friday work schedule only') is incoherent and never tells the agent when to prefer check_hu_working_day over count_hu_working_days or add_hu_working_days.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.